NewsOperation Safe Roads


'Hold the Green' traffic technology being tested in Glendale

green light AP
Posted at 10:28 PM, Nov 17, 2021
and last updated 2021-11-18 06:30:54-05

GLENDALE, AZ — A new radar technology for traffic signals, being tested in Glendale, takes the guesswork out of yellow lights and aims to prevent red-light running crashes.

Every driver has been in the dilemma zone before, the spot in the road where it's unclear how to respond when the traffic signal turns yellow.

"The driver ends up having to decide whether to risk running a red light or getting rear-ended by pressing hard on the brake," said Glendale City Traffic Engineer Tony Abbo.

A few weeks ago, Glendale installed Wavetronix Continuous Tracking Advance Detectors at 63rd Avenue and Peoria Avenue.

"This technology sees a vehicle as it's coming right through from when the time it enters the dilemma zone until the time it leaves the dilemma zone," explained Abbo. "It's making continuous calculations for the possibility of extending that green phase."

Related: Time to Stop: Can longer yellow lights prevent red-light running deaths?

Using radar, the Wavetronix devices detect whether any approaching drivers don't have plenty of time to stop, and they hold the traffic signal on the green light until the driver can safely pass through the intersection.

The detectors can repeat the cycle, holding the green several times for several cars. The system will eventually time out even if there is a car in the dilemma zone, so cross-traffic can move.

"By looking at the crash data before and looking at the crash data after, if we see an improvement, we'll definitely know that we've had success," Abbo said.

The 'hold the green' technology could be especially important in Glendale. An ABC15 Investigators analysis of ADOT red-light-crash data in major Valley cities found Glendale had the worst frequency per capita. ABC15 calculated 95 crashes per 100,000 residents last year.

In 2019, the AAA Foundation found more people died in red-light crashes in Arizona per capita than any other state.

Glendale traffic engineers say they may eventually install Wavetronix sensors on all their major arterials, including Bell Road, Glendale Avenue, and Camelback Road, to make your commute easier and hopefully safer.